Laundry machines such as washing machines, dryers, especially tumble dryers, and combined washers/drawers are known which comprise a user interface which can be, for instance, be arranged on a front panel. The user interface typically provides several user interface elements for selecting or inputting a desired laundry treatment program and/or related parameters for this program. The user interface can also provide symbols, lights, displays or other indicators which allow giving the user a feedback on the selected choices. While switches and push knobs are often used, as a selecting device for a treatment program among a set of available programs, a rotary user interface element such as a rotating or rotary knob, which can also have the functionality of a push button, is often provided. By turning the knob, the user can easily select a desired treatment routine.
The rotary user interface element is a most important element for operating the machine and is used very often. It therefore is of great importance to ensure a long lifetime and also an accurate operation of this user element. Common solutions can lead to misalignment between rotary components and their surrounding parts, which can cause an incorrect or inaccurate rotation of the knob and to damage of the components.
The rotary user element as the primary interface of the machine transmits the first impression to the user of the quality and handling of the appliance. If the user encounters a user interface element that is easy and convenient to handle and provides a constant, steady and solid feedback, and if she or he fells a smooth passage between the several rotational steps during the rotation of the user interface element, she or he gains a good quality impression of the appliance. If otherwise the user interface element has a shaky, unpredictable, or varying response, resulting for example in a rough and variable force needed for the rotation of the user interface element, the user projects this impression on the appliance and gets an impression of overall low quality. Therefore, the user interface should be operated with a constant force feedback and should be reliable and should not block.